remove superfluous build-override

See this comment for rationale.
In short, it's fine to build our simple build script with any opt-level
that is configured for the profile itself.

Author: Byron

Cargo.toml

@@ -221,7 +221,6 @@ panic = "unwind"
 lto = "fat"
 codegen-units = 1
 strip = "symbols"
-build-override = { opt-level = 3 }
 
 [workspace]
 members = [